I try to compile a simple thread_group-example with Borland C++ 5.6 for Win32. I get the following link error: Error: Unresolved external 'boost::thread_group::create_thread(const boost::function0<void, std::allocator<boost::function_base> >&)' referenced from C:\BACPP\SERVICEADAPTER\SRC\SERG.OBJ I have built the boost_thread-bcb-mt-1_34_1.lib with Bjam and Borland. The examples can be created with the library. The MSVC-Variant works without errors. Link-Call: C:\Programme\Borland\CBuilder6\BIN\ILINK32 -Tpe -r -ap -Gn C:\Programme\Borland\CBuilder6\lib\C0X32.OBJ /v -L..\..\Extern\BCB582\BDP\lib -L..\ ..\Xerces\lib\BCB582 -L..\..\Boost\lib\BCB582 -L..\..\LogEngineBA\lib\BCB582 -LC:\Programme\Borland\CBuilder6\lib serg.obj /LIBPATH:..\..\Extern\BC B582\BDP\lib orb_br.lib vdlog_br.lib vport_br.lib /LIBPATH:..\..\Xerces\lib\BCB582 xerces-bor_2_7_0.lib /LIBPATH:..\..\Boost\lib\BCB582 boost_thread-b cb-mt-1_34_1.lib /LIBPATH:..\..\LogEngineBA\lib\BCB582 LogEngine.lib C:\Programme\Borland\CBuilder6\lib\import32.lib C:\Programme\Borland\CBuilder6\li b\cw32mti.lib , serg.exe Turbo Incremental Link 5.60 Copyright (c) 1997-2002 Borland Error: Unresolved external 'boost::thread_group::create_thread(const boost::function0<void, std::allocator<boost::function_base> >&)' referenced from C:\BACPP\SERVICEADAPTER\SRC\SERG.OBJ RLINK32 Version 6.00 (c) Copyright 1992-2002 Borland Software Corporation. Source: #include <iostream> #include <stdio> #include <boost/thread/thread.hpp> #include <boost/bind.hpp> #include <boost/smart_ptr.hpp> #include <vector> using namespace std ; void doCallThreads(std::string text){ printf("Start Thread .......%s\n", text); } void doCallThreadsXXX(){ printf("Start Thread .......\n"); } void doCallsWithThreads(const int countThreads){ // std::vector<boost::thread *> threads; boost::thread_group threads; for(int i = 0; i<countThreads; i++){ //threads.create_thread(boost::bind(doCallThreads, "hhh")); threads.create_thread(&doCallThreadsXXX); // threads.create_thread(&doCallThreadsXXX); printf("Thread %d gestartet\n", (i+1)); } printf("All threads started\n"); // Warten bis alle thread fertig sind threads.join_all(); printf("All threads stopped\n"); } int main(int argc, char* const* argv) { try { doCallsWithThreads(5); cout << "ENDE" << endl ; } catch(std::exception ex) { cout << "Error: " << ex.what() << endl ; throw; } catch(...) { cout << "Error" ; throw; } return 0 ; } Any idea?????